JP7141100B2 - electric valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrically operated valve, and more particularly to an electrically operated valve incorporating a circuit board.

An automobile air conditioner is generally configured by arranging a compressor, a condenser, an expansion device, an evaporator, etc. in a refrigeration cycle. A refrigerating cycle is provided with various control valves, such as an expansion valve as an expansion device, for controlling the flow of refrigerant. 2. Description of the Related Art With the recent spread of electric vehicles and the like, electrically operated valves having a motor as a drive unit are being widely used.

A motor-operated valve is configured by assembling a body containing a valve portion and a motor unit. Some motor units include a circuit board inside the case of the motor unit, on which various circuits for driving and controlling the motor are mounted. As such an electric valve, a circuit board, a stator housing, and a body are connected by conductive parts to reduce electromagnetic interference with surrounding electronic devices, and a ground is also proposed (for example, Patent Document 1). ).

Chinese Patent Application Publication No. 107620824

However, the motor-operated valve of Patent Document 1 requires complicated manufacturing processes such as resin molding after performing welding or crimping between the conductive part and the stator housing. Such a problem can similarly occur in motor operated valves having a built-in circuit board, which are used for various applications other than refrigerating cycles.

One of the objects of the present invention is to easily realize a structure for reducing electromagnetic interference caused by an electrically operated valve.

One aspect of the present invention is an electrically operated valve. This electric valve is constructed by assembling a body having a valve portion therein and a motor unit having a stator covered with a mold resin. The motor unit includes a case integrally formed with the stator by molding resin, and a circuit board arranged in the case. The case has an insertion hole formed by an insertion trace of the mold component in the mold resin. A conductive member is inserted through the insertion hole and is electrically connected to the ground line of the circuit board.

According to this aspect, the insertion marks of the mold parts that are inevitably formed during molding are used as the insertion holes for the conductive members. That is, with a simple structure in which the conductive member is subsequently inserted through the insertion hole formed by molding, the ground area connected to the ground line of the circuit board can be increased, and the electromagnetic interference caused by the motor-operated valve can be reduced.

Another aspect of the invention is also a motor operated valve. This electric valve is constructed by assembling a metal body having a valve portion therein and a motor unit having a stator covered with mold resin. The motor unit includes a case integrally formed with the stator by molding resin, and a circuit board arranged in the case. A conductive member passes through the case and has one end connected to the ground line of the circuit board and the other end connected to the body.

According to this aspect, the conductive member penetrates the case made of molded resin, and the simple structure in which the circuit board and the body are directly connected can increase the ground area connected to the ground line of the circuit board, thereby reducing the electromagnetic interference caused by the motor-operated valve. can be reduced.

ADVANTAGE OF THE INVENTION According to this invention, the structure for reducing the electromagnetic interference by a motor-operated valve can be implement|achieved easily.

1 is a cross-sectional view showing an electrically operated valve according to a first embodiment; FIG. FIG. 2 is a diagram showing the configuration of a stator and its surroundings; 1 is a diagram showing the configuration of a circuit board and its periphery; FIG. FIG. 5 is a cross-sectional view showing an electrically operated valve according to a second embodiment; FIG. 11 is a cross-sectional view showing an electrically operated valve according to a third embodiment; It is a figure showing the electrically-conductive member which concerns on a modification.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for the sake of convenience, the positional relationship of each structure may be expressed based on the illustrated state. Also, in the following embodiments and modifications thereof, substantially the same constituent elements are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

[First embodiment]
FIG. 1 is a cross-sectional view showing an electrically operated valve according to the first embodiment.
The motor-operated valve 1 is applied to a refrigerating cycle of an automotive air conditioner (not shown). This refrigeration cycle includes a compressor that compresses the circulating refrigerant, a condenser that condenses the compressed refrigerant, an expansion valve that throttles and expands the condensed refrigerant and delivers it in the form of mist, and an evaporator that evaporates the refrigerant in the form of mist. An evaporator or the like is provided to cool the air in the passenger compartment by the latent heat of evaporation. Motor operated valve 1 functions as an expansion valve for the refrigeration cycle.

A motor-operated valve 1 is configured by assembling a valve body 2 and a motor unit 3 . The valve main body 2 has a body 5 that accommodates a valve portion. The motor unit 3 is fixed to the body 5 via the connection member 4 and closes the upper end opening of the body 5 .

The body 5 is configured by assembling a first body 6 and a second body 8 in the axial direction. A lower half of the second body 8 is attached to an upper half of the first body 6 . The first body 6 is made of an aluminum alloy, and the second body 8 is made of a copper alloy. In addition, in a modification, the second body 8 may be made of stainless steel (hereinafter referred to as "SUS").

The first body 6 has a prism shape, and is provided with an introduction port 10 at the upper portion of one side surface and an outlet port 12 at the lower portion of the opposite side surface. A valve portion is arranged in a passage that connects the introduction port 10 and the outlet port 12 . Refrigerant from the upstream side (condenser side) is introduced into the body 5 through the introduction port 10 and guided to the valve portion. The refrigerant throttled and expanded by the valve portion is discharged to the downstream side (evaporator side) through the discharge port 12 .

A vertical connecting passage 14 is formed in the center of the first body 6 , the upstream passage 16 communicates with the introduction port 10 and the downstream passage 18 communicates with the outlet port 12 . A stepped circular mounting hole 20 is formed in the first body 6 . The attachment hole 20 gradually increases in diameter upward. The connection passage 14 forms part of the mounting hole 20 . A female thread 22 is formed at a position slightly above the downstream passage 18 in the mounting hole 20 .

The second body 8 has a stepped cylindrical shape whose outer diameter and inner diameter gradually decrease downward, and is assembled to the first body 6 in such a manner that the lower half of the second body 8 is inserted through the mounting hole 20 . ing. The upper half of the second body 8 protrudes above the mounting hole 20 . A male thread 24 that can be screwed with the female thread 22 of the first body 6 is formed on the lower outer peripheral surface of the second body 8 . An annular seal accommodating portion 26 is formed on the outer peripheral surface of the second body 8 slightly above the male thread 24, and a seal ring 28 is fitted thereon. An annular seal accommodating portion 30 is also formed on the outer peripheral surface of the upper portion of the second body 8, and a seal ring 32 is fitted thereon. A flange portion 34 projecting radially outward is provided between the seal accommodating portions 26 and 30 in the second body 8 .

A valve seat forming member 35 is coaxially attached to the lower portion of the second body 8 . The valve seat forming member 35 has a cylindrical shape with a bottom, and its upper portion is coaxially press-fitted into the lower portion of the second body 8 . An annular seal accommodating portion 36 is formed on the lower outer peripheral surface of the valve seat forming member 35, and a seal ring 38 is fitted therein. The valve seat forming member 35 is assembled to the first body 6 at the position of the seal ring 38 thereof.

A valve hole 40 is provided so as to axially penetrate the bottom portion of the valve seat forming member 35 , and a valve seat 42 is formed at the open end of the valve hole 40 . A communication hole 44 is provided at a side portion of the valve seat forming member 35 slightly above the seal accommodating portion 36 to communicate between the inside and the outside. A valve chamber 45 is formed inside the second body 8 and the valve seat forming member 35 . The valve chamber 45 communicates with the upstream passage 16 via the communication hole 44 .

The second body 8 is attached from above the first body 6 so as to be fitted into the attachment hole 20 . At this time, the second body 8 is assembled to the first body 6 while the male thread 24 is screwed into the female thread 22 . Also, the lower end portion of the valve seat forming member 35 is fitted into the mounting hole 20 (connection passage 14). The second body 8 is fastened to the first body 6 by locking the flange portion 34 to the upper surface of the first body 6 . A seal ring 28 is interposed in the fitting portion between the first body 6 and the second body 8 , and a seal ring 38 is interposed between the first body 6 and the valve seat forming member 35 . The former prevents refrigerant from leaking to the outside. Moreover, the latter prevents leakage of the refrigerant through the clearance between the first body 6 and the valve seat forming member 35 (leakage of the refrigerant bypassing the valve portion).

An operating rod 46 extending from the rotor 60 of the motor unit 3 is inserted inside the second body 8 . The operating rod 46 passes through the valve chamber 45 . The operating rod 46 is obtained by cutting a bar material made of non-magnetic metal, and a needle-shaped valve body 48 is integrally provided at the lower part thereof. The valve portion is opened and closed by attaching and detaching the valve element 48 to and from the valve seat 42 from the valve chest 45 side.

A guide member 50 is erected at the center of the upper portion of the second body 8 . The guide member 50 is obtained by cutting a tubular member made of a non-magnetic metal into a stepped cylindrical shape, and has a male thread 52 formed on the outer peripheral surface of the central portion in the axial direction. The lower end portion of the guide member 50 has a large diameter, and the large diameter portion 54 is coaxially fixed to the upper center of the second body 8 . The guide member 50 slidably supports the operating rod 46 in the axial direction by its inner peripheral surface, and slidably supports the rotation shaft 62 of the rotor 60 by its outer peripheral surface.

A spring receiver 49 is provided on the operating rod 46 slightly above the valve body 48 , and a spring receiver 56 is also provided on the bottom of the guide member 50 . A spring 58 (functioning as a "biasing member") is interposed between the spring bearings 49 and 56 to bias the valve body 48 in the valve closing direction.

On the other hand, the motor unit 3 is configured as a three-phase stepping motor including a rotor 60 and a stator 64. As shown in FIG. The motor unit 3 has a cylindrical can 66 with a bottom, the rotor 60 is arranged inside the can 66, and the stator 64 is arranged outside. The can 66 is a bottomed cylindrical member that covers the space in which the valve body 48 and its drive mechanism are arranged and that encloses the rotor 60. The can 66 acts as an inner pressure space (internal space) where the pressure of the refrigerant acts. and an outer non-pressure space (external space). The can 66 is made of a non-magnetic metal, and is coaxially fixed to the second body 8 by inserting its lower end opening into the upper end opening of the second body 8 and welding it. A space surrounded by the can 66 and the second body 8 forms the pressure space.

The stator 64 is configured by arranging a plurality of salient poles 72 at regular intervals on the inner peripheral portion of the laminated core 70 . The laminated core 70 is configured by laminating disc-shaped cores in the axial direction. A bobbin 74 around which a coil 73 (electromagnetic coil) is wound is attached to each salient pole 72 . These coils 73 and bobbins 74 constitute a "coil unit 75". In this embodiment, three coil units 75 for supplying three-phase current are provided at intervals of 120 degrees with respect to the central axis of the laminated core 70 .

The stator 64 is provided integrally with the case 76 of the motor unit 3 . That is, the case 76 is obtained by injection molding a corrosion-resistant resin material. The stator 64 is covered with molding resin obtained by injection molding (also called “insert molding” or “molding”). Hereinafter, the molded product of the stator 64 and the case 76 will also be referred to as a "stator unit 78".

The stator unit 78 has a hollow structure and is assembled to the body 5 while coaxially passing through the can 66 . The connecting member 4 is configured as a plate-like member having an L-shaped cross section. This fixation is performed by fastening bolts (not shown). A seal ring 32 is interposed in the fitting portion between the lower inner peripheral surface of the case 76 and the second body 8 . This prevents an external atmosphere (such as water) from entering the motor-operated valve 1 .

The rotor 60 includes a cylindrical rotor core 102 assembled to the rotating shaft 62 and magnets 104 provided along the outer circumference of the rotor core 102 . The rotor core 102 is attached to the rotating shaft 62 . The magnet 104 is magnetized (magnetized) with a plurality of poles in its circumferential direction.

The rotary shaft 62 is a cylindrical shaft with a bottom, and is fitted around the guide member 50 with its open end facing downward. A female thread 108 is formed on the lower inner peripheral surface of the rotary shaft 62 and meshes with the male thread 52 of the guide member 50 . With such a configuration, the rotation of the rotor 60 causes the screw feed mechanism to function, and the rotor 60 moves (elevates) in the axial direction.

The upper portion of the operating rod 46 is reduced in diameter, and the reduced diameter portion 110 penetrates the bottom portion 112 of the rotating shaft 62 . An annular stopper 114 is fixed to the distal end of the reduced diameter portion 110 . On the other hand, a spring 116 is interposed between the base end of the reduced diameter portion 110 and the bottom portion 112 to bias the operating rod 46 downward (ie, in the valve closing direction). With such a configuration, when the valve is opened, the operating rod 46 is displaced integrally with the rotor 60 in such a manner that the stopper 114 is locked to the bottom portion 112 . On the other hand, when the valve is closed, the spring 116 is compressed by the reaction force that the valve element 48 receives from the valve seat 42 . Due to the elastic deformation of the spring 116 at this time, the valve body 48 can be pressed against the valve seat 42 by its reaction force, and the seating performance (valve closing performance) of the valve body 48 can be enhanced.

The motor unit 3 has a circuit board 118 outside the can 66 . The circuit board 118 is fixed inside the case 76 . In this embodiment, various circuits functioning as a control section and a communication section are mounted on the lower surface of the circuit board 118 . Specifically, a drive circuit for driving the motor, a control circuit (microcomputer) that outputs control signals to the drive circuit, a communication circuit for the control circuit to communicate with an external device, each circuit and motor (coil) A power supply circuit and the like for supplying power are mounted. The upper end of the case 76 is closed with a lid 77 . A circuit board 118 is arranged in the space below the lid 77 in the case 76 .

A pair of terminals 137 connected to the coil 73 extend from the bobbin 74 and are connected to the circuit board 118 . A power supply terminal, a ground terminal, and a communication terminal (also collectively referred to as “connection terminals 81”) extend from the circuit board 118 and pass through the side wall of the case 76 to be drawn to the outside. A connector portion 79 is provided integrally with the side portion of the case 76 , and connection terminals 81 are arranged inside the connector portion 79 .

An insertion hole 90 extending parallel to the axis is provided at a specific position on the upper portion of the case 76 . The insertion hole 90 is an insertion trace of the mold component in the mold resin. That is, in this embodiment, when the stator unit 78 is molded, the stator 64 is supported by a plurality of (three in this embodiment) pins erected in a mold (not shown). These pins are mold parts that act as struts. Since the pins are columnar and support the axial end face of the laminated core 70, the case 76 after molding is formed with insertion holes 90 having a circular cross section as insertion marks for the pins. A portion of the upper end surface of the laminated core 70 is exposed inside the insertion hole 90 .

In this embodiment, the ground line 119 of the circuit board 118 and the laminated core 70 are electrically connected using the insertion hole 90 . That is, the surface of the circuit board 118 on which the ground line 119 is formed and the upper end surface of the laminated core 70 are opposed to each other in the axial direction of the laminated core 70 . It contacts the line 119 and the other end contacts the laminated core 70 . Although the surface of the laminated core 70 is subjected to an insulation treatment (coating), the contact surface with the coil spring 92 is polished to remove the insulation treatment. The coil spring 92 is made of conductive stainless steel (spring steel) and functions as a “conductive member” and an “elastic member”. Due to the appropriate elastic force of the coil spring 92, the abutting state of both ends can be stably maintained, and the conductive state between the two can be ensured.

Next, the arrangement configuration of the conductive members will be described in detail.
FIG. 2 is a diagram showing the configuration of the stator 64 and its surroundings. (A) is a cross-sectional view of the stator unit 78 corresponding to the cross-section taken along line AA in FIG. (B) is a diagram showing only the stator 64 (state before resin molding). For reference, FIG. 2A shows the can 66, the rotor 60, the insertion hole 90, and the coil spring 92 (see two-dot chain lines).

Since the motor unit 3 is a three-phase motor, the coil units 75 are provided at equal intervals around the axis of the rotor 60 as shown in FIG. 2(A). As shown in FIG. 2B, slots 120a to 120c (collectively referred to as "slots 120" when not distinguished) are formed in the inner peripheral portion of the laminated core 70 at intervals of 120 degrees with respect to the axis L. is provided. In each slot 120, salient poles 122a to 122c (generically referred to as "salient poles 122") projecting radially inward from the center thereof are formed. (collectively referred to as "coil 73") are assembled. A slit 124 having a U-shaped cross section is also formed between the slots 120 adjacent to each other to optimize the magnetic path.

The magnet 104 faces the salient poles 122a to 122c via the can 66. As shown in FIG. In this embodiment, as shown in FIG. 2A, the magnet 104 is magnetized with 10 poles, but the number of poles can be set appropriately.

As described above, three pins (mold parts) are used to support the stator 64 during molding of the stator unit 78 . Since these pins are arranged at intervals of 120 degrees around the axis L of the stator 64, three insertion holes 90 are formed correspondingly. A coil spring 92 (conductive member) is inserted through one of the three insertion holes 90 and is provided so as to abut on a portion of the upper surface of the laminated core 70 . In this embodiment, as shown in the drawing, the abutting portions are set between the pair of slits 124, but may be set at other positions on the upper surface of the laminated core 70. FIG.

FIG. 3 is a diagram showing the configuration of the circuit board 118 and its periphery. (A) is a plan view showing a state before the lid body 77 and the circuit board 118 are assembled in the stator unit 78. FIG. (B) is a bottom view of the circuit board 118. FIG. For convenience of explanation, only the ground line 119 is shown in a colored portion in FIG.

As shown in FIG. 3A, two communication terminals (input terminal 134 and output terminal 132), a power supply terminal 130 and a ground terminal 136 are molded in the case 76. As shown in FIG. A pair of terminals 137 extend from each coil 73 and are connected to the circuit board 118 . A coil spring 92 is inserted through one of the three insertion holes 90 formed in the case 76 .

3B, a ground line 119 is formed on the bottom surface of the circuit board 118 (the area where the ground line 119 is formed is also called a "ground line forming surface"). is provided with a connection region 139 to which the ground terminal 136 is soldered and a connection region 138 with which the upper surface of the coil spring 92 abuts.

Returning to FIG. 1 , the electric valve 1 configured as described above functions as an electric expansion valve whose valve opening degree can be adjusted by drive control of the motor unit 3 . That is, based on a command from an external device (not shown), the control circuit sets a control amount (the number of motor driving steps) for realizing the target opening, and generates a driving signal (driving pulse) for realizing this. Output to the drive circuit. The drive circuit supplies a three-phase drive current (drive pulse) to each coil 73 at set timings. Thereby, the rotor 60 rotates with high resolution. At this time, if the valve body 48 is separated from the valve seat 42 and the valve is open, the biasing force of the spring 116 causes the stopper 114 to abut against the rotating shaft 62 , and the operating rod 46 and thus the valve body 48 are integrated with the rotor 60 . Operate.

The rotor 60 moves vertically by a screw feed mechanism between the guide member 50 and the guide member 50 . That is, the valve body 48 translates in the opening/closing direction of the valve portion, and the opening degree of the valve portion is adjusted to the set opening degree. This screw feed mechanism converts the rotational motion of the rotor 60 about the axis into translational motion (straight motion) in the axial direction of the operating rod 46 to drive the valve body 48 in the opening and closing direction of the valve portion.

As described above, according to the present embodiment, the insertion marks of the pins (mold parts) used as supports when molding the stator unit 78 are used as the insertion holes 90 for the coil springs 92 (conductive members). be done. Since there is no resin coating on the portion of the laminated core 70 that was in contact with the pin, that portion is connected to the conductive member and used as a conductive path.

That is, by subsequently inserting the coil spring 92 into the insertion hole 90 formed by molding, the ground line 119 of the circuit board 118 and the laminated core 70 can be electrically connected, thereby reducing the electromagnetic interference caused by the electric valve 1. can. Further, by using an elastic member as the conductive member, the conductive member is brought into elastic contact with the circuit board and the core, respectively. Therefore, the electrically conductive member can be stably maintained without falling or the like. That is, according to the present embodiment, since it is not necessary to use joining means such as welding or crimping for installation of the conductive member, it is possible to easily realize a structure for reducing electromagnetic interference.

[Second embodiment]
FIG. 4 is a cross-sectional view showing an electrically operated valve according to the second embodiment.
The electric valve 201 is configured by assembling a valve body 202 and a motor unit 203 . The upper end surface of the valve body 202 and the lower end surface of the motor unit 203 are in contact with each other, and are fastened and fixed by bolts (not shown).

An insertion hole 290 extending parallel to the axis is provided at a specific position in the lower portion of the case 276 . The insertion hole 290 is an insertion trace of the second mold component (pin) in the mold resin, similar to the upper insertion hole 90 . In the case 276 after molding, an insertion hole 290 (functioning as a "second insertion hole") having a circular cross section is formed as an insertion trace of the pin. A portion of the lower end surface of the laminated core 70 is exposed inside the insertion hole 290 . On the other hand, a concave portion 294 is provided on the upper surface of the first body 206 at a position facing the mounting hole 20 . The recess 294 is a circular groove having the same cross-sectional shape as the insertion hole 290 and coaxially faces the insertion hole 290 . A coil spring 292 is arranged in a space defined by these insertion holes 290 and 294 .

As a result, one end of the coil spring 292 contacts the laminated core 70 and the other end contacts the first body 206 . The coil spring 292 is made of conductive stainless steel (spring steel) and functions as a “second conductive member” and an “elastic member”. Due to the appropriate elastic force of the coil spring 292, the abutting state of both ends can be stably maintained, and the conductive state between the two can be ensured.

With such a configuration, ground line 119 of circuit board 118 and body 205 are serially (linearly) connected via coil spring 92 , laminated core 70 and coil spring 292 . As a result, the ground area connected to the ground line 119 of the circuit board 118 can be made larger than in the first embodiment, and the electromagnetic interference caused by the motor operated valve 201 can be reduced more effectively. In this embodiment, the coil springs 92 and 292 are common parts. By sharing parts in this way, the cost of parts can be reduced.

[Third embodiment]
FIG. 5 is a cross-sectional view showing an electrically operated valve according to the third embodiment.
The electric valve 301 is configured by assembling a valve body 302 and a motor unit 303 . An elongated pin 392 (functioning as a “conductive member”) is provided to pass through the case 76 . One end of the pin 392 is connected to the ground line 119 (see FIG. 3B) of the circuit board 118, and the other end is connected to the first body 306.

Pin 392 is molded into case 276 during molding. By connecting the ground line 119 of the circuit board 118 and the body 305 with the single pin 392 in this manner, a large ground area can be secured and electromagnetic interference caused by the motor-operated valve 301 can be effectively reduced.

Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to those specific embodiments, and that various modifications are possible within the scope of the technical idea of the present invention. Nor.

FIG. 6 is a diagram showing a conductive member according to a modification. (A) is a longitudinal sectional view, and (B) is a bottom view.
In the first and second embodiments, coil springs are exemplified as conductive members. Although not described in each embodiment, a tip contact type spring 192 as shown in FIGS. 6A and 6B may be employed as such a spring. The ends of the windings of the springs 192 protrude in the axial direction, and when the tips come into contact with the surface of the laminated core 70, the insulation coating of the laminated core 70 can be broken to allow conduction. The tip of the spring 192 functions as a "tip contact portion" that can contact the surface of the laminated core 70 with a pressing force due to elastic deformation. This eliminates the need for polishing the laminated core 70 . Alternatively, pins, rivets, leaf springs or other conductive members may be employed. A leaf spring having a tip contact portion, or a pin whose tip contacts the stator (core) while being flexibly deformed may be employed. A metal material is preferable as the conductive member, but a resin material containing a conductive filler may be used to ensure conductivity. A conductive powder-impregnated rubber or the like may be employed. If an elastic member such as a spring is employed as in the above embodiment, the dimensional error in the connection direction can be absorbed by the expansion and contraction of the elastic member, so there is an advantage that the dimensional freedom (design freedom) of the conductive member is increased. In this modified example, the laminated core 70 is exemplified as the "conducting object" with which the tip contact portion contacts, but other members coated with insulation (members that can serve as a ground area) may be used.

In each embodiment, as shown in FIG. 3A, an example is shown in which the coil spring 92 is arranged in one of the three insertion holes 90, but the coil springs 92 are also arranged in the remaining insertion holes 90. However, it may have an electromagnetic interference suppression function (conduction function, grounding function). That is, the conductive member may be inserted into one or more of the plurality of insertion holes formed by the insertion traces of the mold parts and electrically connected to the ground line of the circuit board.

In each of the embodiments, the body is made of metal, but it may be made of resin or other non-conductive material as long as the ground line of the circuit board and the core of the stator are only electrically connected.

In the first and second embodiments, the configuration in which the conductive member is arranged between the axially facing surfaces of the ground line forming surface of the circuit board and the end surface of the core is exemplified. In other words, the conductive member connects the circuit board and the core at the shortest distance by contacting one end surface of the conductive member with the end surface of the core and the other end surface with the ground line forming surface of the circuit board. In a modification, for example, the side surface of the conductive member may be in contact with the side surface of the core. Thereby, there is a possibility that the contact area between the conductive member and the core can be increased. However, from the viewpoint of space saving, it is preferable to configure as in the first and second embodiments so that the length of the conductive member is minimized. The same applies to the conductive member arranged between the core and the body.

In another modification, the ground line may be arranged on the side surface of the circuit board or the inner peripheral surface of the hole, and the side surface of the conductive member may be brought into contact with the ground line. The same applies to the conductive member arranged between the core and the body.

In the third embodiment, an example in which the pin 392 is molded on the case 76 is shown. In a modification, an insertion hole (insertion trace) passing through the case 76 may be formed during molding, and the pin 392 may be inserted through the insertion hole afterward.

In each embodiment, a laminated core (laminated magnetic core) is exemplified as the core of the stator. Alternatively, a dust core or other core may be employed. A dust core is also called a "dust core" and is obtained by pulverizing a soft magnetic material and coating it with a non-conductive resin or the like, kneading the powder with a resin binder, compression molding, and heating. In the laminated core, it is easy for magnetic flux to pass in the in-plane direction of each core, but it is difficult for magnetic flux to pass in the lamination direction. In this respect, unlike the laminated core, the compact core has isotropic magnetic properties and enables the design of a stator having a three-dimensional magnetic circuit. In addition, since the compact core can be formed into any shape during compaction, the degree of freedom in design is high, and it is also possible to form the insertion hole at the same time during compaction.

In each embodiment, the configuration in which the drive circuit, the control circuit, the communication circuit, and the power supply circuit are mounted on the lower surface of the circuit board is exemplified, but the circuits to be mounted can be changed as appropriate. For example, the drive circuit and power supply circuit may be implemented, while the control circuit may be located external to the motor operated valve. Also, each circuit may be mounted on the upper surface of the circuit board. In that case, the ground line may extend to the bottom surface.

In the first embodiment, the core of the stator and the circuit board are connected via the conductive member. However, if the conductive member has a sufficiently large volume, the connection to the core may be omitted good. In other words, the electromagnetic interference may be reduced by the conductive member itself.

In each embodiment, a PM stepping motor is used as the motor unit, but a hybrid stepping motor may be used. Also, in the above embodiment, the motor unit is a three-phase motor, but other motors such as two-phase, four-phase, and five-phase motors may be used. The number of electromagnetic coils in the stator is not limited to three or six, and may be appropriately set according to the number of phases of the motor. Also in this case, the stator may be composed of a core, and a conductive member such as a coil spring may be interposed between the circuit board and the core.

In each embodiment, an example is shown in which the motor-operated valve is configured as a two-way valve having one outlet port for one inlet port. In a variant, it can be configured as a three-way valve with two outlet ports for one inlet port, or as a four-way valve with two outlet ports for two inlet ports.

The motor-operated valve of each embodiment is suitably applied to a refrigeration cycle that uses a CFC substitute (HFC-134a) as a refrigerant, but it can also be applied to a refrigeration cycle that uses a refrigerant with a high operating pressure, such as carbon dioxide. is. In that case, an external heat exchanger such as a gas cooler is arranged in the refrigeration cycle instead of the condenser.

In each embodiment, the electric valve is configured as an expansion valve, but it may be configured as an on-off valve or a flow control valve that does not have an expansion function.

In each embodiment, an example in which the electric valve is applied to the refrigerating cycle of an automotive air conditioner is shown, but the electric valve is applicable not only to vehicles but also to air conditioners equipped with an electric expansion valve. Also, it can be configured as an electrically operated valve that controls the flow of fluid other than refrigerant.

It should be noted that the present invention is not limited to the above-described embodiments and modifications, and can be embodied by modifying constituent elements without departing from the scope of the invention. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments and modifications. Also, some constituent elements may be deleted from all the constituent elements shown in the above embodiments and modifications.

Reference Signs List 1 electric valve 2 valve main body 3 motor unit 5 body 6 first body 8 second body 10 inlet port 12 outlet port 40 valve hole 46 operating rod 48 valve body 50 guide member 60 Rotor 64 Stator 66 Can 70 Laminated Core 73 Coil 74 Bobbin 76 Case 77 Lid Body 78 Stator Unit 81 Connection Terminal 90 Insertion Hole 92 Coil Spring 118 Circuit Board 119 Ground Line 120 Slot 122 salient pole 124 slit 130 power supply terminal 132 output terminal 134 input terminal 136 ground terminal 137 terminal 138 connection area 201 electric valve 202 valve body 203 motor unit 205 body 206 first Body, 276 case, 290 insertion hole, 292 coil spring, 294 recess, 301 electric valve, 302 valve body, 303 motor unit, 305 body, 392 pin.

Claims (5)

A motor-operated valve configured by assembling a body having a valve portion therein and a motor unit having a stator covered with a mold resin,
The motor unit is
a case integrally formed with the stator by the mold resin;
a circuit board disposed within the case;
including
The case has an insertion hole formed by an insertion trace of the mold part in the mold resin,
a conductive member is inserted through the insertion hole and is electrically connected to the ground line of the circuit board;
one end side of the conductive member is connected to the ground line and the other end side is connected to the core of the stator;
a surface of the circuit board on which the ground line is formed and one end surface of the core face each other in the axial direction of the core, and the conductive member is interposed between the two;
An electrically operated valve , wherein the conductive member is an elastic member . 2. The electrically operated valve according to claim 1 , wherein the conductive member has a tip contact portion capable of contacting the surface of the conductive object with a pressing force due to elastic deformation. A motor-operated valve configured by assembling a body having a valve portion therein and a motor unit having a stator covered with a mold resin,
The motor unit is
a case integrally formed with the stator by the mold resin;
a circuit board disposed within the case;
including
The case has an insertion hole formed by an insertion trace of the mold part in the mold resin,
a conductive member is inserted through the insertion hole and is electrically connected to the ground line of the circuit board;
the body is made of metal,
The case has a second insertion hole formed by an insertion trace of the second mold component,
A motor -operated valve, wherein a second conductive member is inserted through the second insertion hole and connects the core of the stator and the body. 4. A motor-operated valve according to claim 3 , wherein said second conductive member is an elastic member. 5. The electrically operated valve according to claim 4 , wherein the conductive member and the second conductive member are the same coil spring.

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